7 – ASUS Radeon HD 6950 Power consumption and Overclocking

For the power consumption and overclocking test, I used the upcoming FurMark 1.9.0 (still not released due to a little lack of time but it should be there shortly!). The graphics workload in the new FurMark 1.9.0 has been slightly increased, leading to more power consumption (few watts in more). But this extra graphics workload can make the difference with high overclocking settings.

The total power consumption of my testbed in idle is 110W (HD 6950 with default clocks).

The Radeon HD 6950 integrates a new power draw limiter called PowerTune:

To overclock a Radeon HD 6950, you must set the PowerTune to +20% in Catalyst Control Center (CCC):

With default GPU clock speed (810MHz), the total power consumption of the testbed stressed by FurMark 1.9.0 is 329W for a max GPU temperature of 91°C (FurMark settings: 1920×1080, fullscreen, Burn-in mode, dynamic background, no AA, no postfx).

We can the calculate the power consumption of ASUS’s HD 6950. The Corsair AX1200 PSU has an efficiency factor of around 0.9 (see this article, there is a graph of the AX1200 efficiency).
P = (329-110) * 0.9P = 197 watts

Under the same conditions, a Radeon HD 6970 shows a power consumption of: 260W for a GPU temperature of 93°C.

To overclock the ASUS HD 6950, I used ASUS SmartDoctor 5.74. SmartDoctor is ASUS’s overclocking utility:

Using SmartDoctor, and by modifying the GPU core clock only and GPU voltage, I managed to get a stable value under FurMark 1.9.0 for a GPU clock of 840MHz. Actually 840MHz is the max clock speed you can set in SmartDoctor and in other overclocking utilities.
To validate this GPU overclocking I ran FurMark 1.9.0 and 3DMark11 Extreme mode benchmarks.

To reproduce such overclocking test, I recommend you to have some quality hardware, because we exceed the electric specifications of the system. In my case, a GIGABYTE A-UD5 motherboard and a high-end PSU: Corsair’s AX1200!

Here is a comparative table of the power consumption of the card ALONE (not the total power consumption of the system):

– Now that the time finally came to play Crysis as it was supposed to be played, I gotten myself two new Geforces instead of two new Radeons, lol. No regrets though. The game runs fine. It’s actually cpu limited now. 😀

@Psolord: thanks for the links bug. Fixed!
And yes the HD6950 score in Crysis is correct. I will bench again HD 6970 and HD 6950 when new drivers will be available because some scores (especially in OpenGL) are not coherent. For Crysis, I used the integrated GPU benchmark with default settings (I forgot the resolution sorry).

I just bought the ASUS EAH6950 2GB video card running on a 24inch LED monitor but i find the graphics not being sharp. The edges around the fonts are abit fuzzy and videos are not sharp as well. Anyone know why this is so?

Oh yeah, found it so annoying how i had to play around with the scaling option to get full display on my monitor!